1. Field of Invention
This invention relates to a system and a method for generating emulsified fuels for improved fuel efficiency in a combustion device to enhance its performance with reduced specific fuel consumption rate and emissions, comprising at least a continuous phase fuel, a dispersed phase component, and an infrared radiation source that spans at least a portion of 3-16 μm (micrometers) wavelength spectrum. In said system and method the continuous phase fuel and/or dispersed phase component are exposed to said infrared before or during emulsification process. The continuous phase fuel may be selected from fossil fuels, biofuels, alcohol fuels, vegetable oils, or any combustible liquid fuels, while the dispersed phase component may be oxygen, hydrogen, nitrogen, carbon monoxide, methane, propane, butane, any other petroleum gas, hydrogen peroxide, or water. Such emulsified fuels can be used in combustion devices such as internal combustion engines, boilers, burners, or gas turbines.
2. Description of Prior Art
The Clean Air Act of 1963, and later amendments, mandates the reduction of airborne contaminants, smog and air pollution in general from both stationary and mobile sources. Numerous techniques were attempted to address these requirements, including the use of emulsified fuels with a hope to improve combustion efficiency of hydrocarbon fuel blends. For examples, water-in-hydrocarbon emulsions have been extensively studied and shown some success in reducing targeted emissions from diesel engines, but unfortunately not without facing serious technical problems due to the stability of emulsions and the pollutants produced by the burning of emulsifying agent. Inventions in this field may be found in U.S. Pat. Nos. 4,388,893, 5,997,590, 6,800,154, 7,041,145, and 7,704,288, to name a few. In spite of the theoretical potential of emulsified systems, aforementioned problems casted a shadow over the feasibility of commercial applications of such techniques.
In theory, emulsions are made up of a dispersed and a continuous phase. The dispersed phase exhibits a surface and is covered by a different surface of continuous phase; the boundary between these phases is called the interface. It is a common belief that the dispersed particles are assumed to be statistically distributed in the continuous phase. As such, energy input through homogenizing process is needed to initially form an emulsion. This energy can be applied through shaking, stirring, vibrating, or by the use of high-speed propelling, ultrasonic, or high pressure means. Nonetheless, emulsions are unstable and, over time, tend to revert to the stable state of the phases comprising the emulsion.
In practical applications, the difficulty in making a useful emulsion of hydrocarbon fuel is on its high interfacial tension with the dispersed phase. Furthermore, increasing temperature of the fuel, through fuel delivery system of a combustion device, may accelerate destabilization. Surface active substances (called surfactants, emulsifier, emulsifying agent, or emulgent) can increase the kinetic stability of emulsions greatly so that they may be added to the mixture for making and maintaining the emulsion. However, these additives are expensive and may add unwanted pollutants to the emissions during combustion, which would be better off to avoid, if possible.
Accordingly, one main challenge remains in the industry is to develop a stable and sustainable emulsion system without the need for relatively large amount of stabilizing agents. It is one of the objects of the present invention to address and meet this need.
After years of research the present inventor had discovered the use of infrared radiation in the 3-16 μm wavelength spectrum, defined as “mid-infrared” by U.S. NASA but “far infrared” in Japanese convention, for enhancing combustion efficiency of hydrocarbon fuels in internal combustion engines. It resulted in the inventions of the fuel combustion enhancement devices disclosed in the U.S. Pat. Nos. 6,026,788, 6,082,339 and 7,617,815.
Photoexciting hydrocarbons with infrared photons shorter than 20 μm (micrometers) in wavelengths has been described theoretically and experimentally in Organic Chemistry textbook. When a photon is absorbed by a molecule, it ceases to exist and its energy is transferred to the molecule in one of vibrational, rotational, electronic, and translational forms. Numerous organic compounds, such as hydrocarbons, are known to be infrared-active and absorb infrared photons in 3-16 μm wavelengths to cause molecular vibrations in stretching and/or bending movement. Thus, exciting hydrocarbons with infrared in said wavelengths can increase the internal energy of hydrocarbon molecules and improve reaction rate for better fuel efficiency in engines. The present inventor has proven the underlining science of infrared-excitation effect on hydrocarbon fuels and the results were published by the SAE International (Paper No. 2010-01-1953) entitled “Infrared-excitation for Improved Hydrocarbon Fuels' Combustion Efficiency-Concept and Demonstration.”
Moreover, the present inventor was also trying to explore new IR-related technologies that further improve fuel efficiency in different research fronts. Among them, one is fuel emulsion, purposely adding various gaseous or liquid components to fossil or alternative fuels for a more efficient fuel admixture. Although by definition an emulsion is a mixture of two or more immiscible liquids, the term emulsion is extended to dispersing gaseous component in liquid fuel throughout this invention.
In preliminary lab experiments with diesel fuels and vegetable oils, the present inventor found that after exciting the fuels or oils with infrared emitted from the ceramics as described in aforementioned U.S. patents by the present inventor, they become relatively susceptible to dispersion of gaseous or liquid components, such as water, air, or hydrogen. This is believed that the molecules in the continuous phase fuel or oil are excited by absorbing infrared in 3-16 μm. The excited molecules tend to break away from forming large clusters or aggregates, resulting in reduced interfacial tension with the dispersed phase and helping homogenizing the mixture. Though such infrared assisted emulsion is short haul, only lasting for about 3-5 minutes before the majority of infrared photons have escaped from the system, it is suitable for “emulsion-on-demand” applications, in which it only takes a few seconds for the emulsified fuel from being made to being burned in a combustion device.
As described above, the prior art failed to teach the use of IR-excitation in the making of fuel emulsions to improve fuel efficiency of the emulsified fuel in a combustion device for increased performance with reduced specific fuel consumption rate and emissions.